A tunnel was damaged on Tuesday at a plutonium handling facility at the Hanford Nuclear Reservation in Washington state, leading authorities to evacuate some workers at the site and instruct others to take cover, a spokesperson for the site said in a release.

The US Department of Energy said it has activated its emergency operations protocol in Hanford, a small agricultural community in south-central Washington, about 200 miles from Seattle. It came after an alert at the 200 East Area, which is home to numerous solid waste sites.

Workers in one building were evacuated, and others in the immediate vicinity were ordered to take cover and turn off ventilation systems as a precaution after minor damage was discovered in the wall of a transport tunnel, a spokeswoman for the Department of Energy told Reuters.

The Hanford Nuclear Reservation. (Photo: US Department of Energy( Photo: Bellona Archive

“There is evidence of a small sunken area of soil that covers the tunnel, but no collapse,” the spokeswoman said. “There is no evidence of a release and no reports of any injuries at this time.

Local media in Washington state had earlier reported the tunnel had collapsed.

Energy Department officials in Hanford confirmed this in a later statement, “There are concerns about subsidence in the soil covering railroad tunnels near a former chemical processing facility. The tunnels contain contaminated materials.”

Cleaning up radioactive materials at the Hanford site, which is roughly half the size of Luxembourg, been one of the Energy Department’s priorities for years. Reactors located at Hanford produced plutonium for America’s nuclear weapons program and uranium metal fuel for commercial reactors. Plutonium production ended in 1980 and the cleanup program began in 1989.

Bellona will monitor the situation closely,” said Nils Bøhmer, Bellona’s general director and nuclear physicist. “It highlights the enormous challenges that the US faces in cleaning up its Cold War Legacy, which will take decades to restore.”

Robert Alvarez, a former Energy Department official, told the Washington Post that rail cars at Hanford carry spent fuel from the reactor area along the Columbia River to the site’s reprocessing facility, where plutonium and uranium are then extracted. Alvarez said that contaminated pieces of equipment, including the rail cars, have been left in the tunnels.

In an update to their early statement, the Energy Department said that the soil had “subsided” in in a small area over one of the tunnels next to Hanford’s Plutonium Uranium Extraction Facility, also known as PUREX.

“There is no indication of a release of contamination at this point,” the Energy Department’s update said. “Responders are getting closer to the area where the soil has subsided for further visual inspection. The subsidence of soil was discovered during a routine surveillance of the area by workers.”

The tunnels are hundreds of feet long, with approximately eight feet of soil covering them, the Energy Department added. The depth of the subsidence of soil appears to be about a meter deep.

The Hanford site was established in 1943 as part of the Manhattan Project, and its history has been one of calamitous nuclear contamination. It’s plutonium reactor, the world’s first, immediately contaminated the Columbia River.

The Hanford Nuclear Reservation in 1960. (Photo: US Department of Energy)

Between 1947 and 1956, as the arms race between America and the Soviet Union ramped up, five new plutonium production reactors were added, as were two chemical reprocessing plants and 81 underground waste storage tanks. Hanford’s contamination stretched down the US Pacific Coast between 1950 and 1960 as all of its reactors ran at full capacity.

Then, in 1974, officials detected a 430,000-liter leak in one of the sites waste storage tank. Two years later, an explosion at the Hanford Site’s Plutonium Finishing Plant blew out a quarter-inch-thick window and showered a worker with nitric acid and radioactive glass.

US President Lyndon Johnson had ordered Hanford’s shutdown back in 1964, but the process would continue stutter-step until decades later, it was finally closed in 1988.

The administration of Donald Trump has vowed huge budget slashes for energy related programs in the United States, but he has left Hanford cleanup programs fully funded.

The current budget for the current fiscal years is some $2.3 billion, with $1.5 billion of that going to manage and treat 211 million liters of radioactive liquid waste stored in at the site’s underground tanks.